Slug-positioner for ball-making machines



July 30, 1957 T. E. LEWIS, JR 2,800,814

SLUG-POSITIONER FOR BALL-MAKING MACHINES Fild July 51, 1953 I FIE 1- N 1 I L ZiT:ii J

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United States SLUG-POSITIONER- non BALL-MAKING MACHINES Thomas E. Lewis, Jr., Johnstown,'-Pa., assignor to United This invention relates to automatic machines for hotforging metal slugs and, in particular, to an improved means for positioning a heated slug of metal so it will be properly engaged by a pair of opposed shaping dies.

Steel balls for grinding mills and the like are hot-forged on automatic machines incorporating opposed hemispherical shaping dies and a reciprocating shear blade which cuts off successive slugs from a heated bar and carries them to a position between the dies, one of which reciprocates toward and from the other. Frequently the initial eifect of the blade is to rnisaline slightly or distort the end of the bar protruding from a hole in a shear plate. This causes the axis of the slug to be out "of alinement with the common axis of the dies when the slug is sheared off and positioned between the latter. Ball making machines have therefore been provided with a member adapted to advance between the open dies for positioning the slug in properly'alined relation to the dies but the mechanism for actuating such means is complex in structure and diflicult to maintain. The positioning member, furthermore, frequently fails to locate the slug accurately with the result that many out-of-round balls are produced which have to be scrapped. It is accordingly the object of my invention to provide a slug positioner for ball- .making machines or the like which is very simple, un-

likelyrto .get out of adjustment and capable of positioning f slugs with such accuracy that the dies properly'shape them into spheres within the required tolerance limits.

In a preferred embodiment of my invention, I provide a guide immediately adjacent the forming dies and mount therein for reciprocation toward and from the dies a plunger having a finger thereon adapted to project between the dies when they are open, i. e., when the reciprocating die is retracted from the fixed die. I also employ means constantly urging the plunger toward the dies and provide a stop to determine the inwardmost position of the plunger and finger. Finally, I utilize means moving with the reciprocable die to displace the plunger and retract the finger to an out-of-the-way position as the die is pressed home.

A complete understanding of the invention may be obtained from the following detailed description and explanation of the present preferred embodiment illustrated in the accompanying drawings. In the drawings,

Figure 1 is a plan view showing the improved positioner with the parts in the positions they occupy at the end of one operating cycle and the start of the next;

Figure 2 is a similar view showing the plunger fully retracted and the moving die partially retracted;

Figure 3 is a sectional view taken along the plane of line IIIIII of Figure 2, showing parts in elevation; and

Figure 4 is an end elevation such as would be seen by looking from the right of Figure 3.

Referring now in detail to the drawings and, for the present, to Figure 1, a ball-making machine comprises a main frame having a fixed hemispherical die 11 seated therein provided with a spring-pressed ejector pin 11a.

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the slug forward into'position for shaping between die 11 and a similar, opposed cooperating die 16 seated in a head 17 reciprocating toward and from die 11. The reciprocation of the shear blade and the moving die are properly coordinated time-wise by known means to give the desired order of operation. The parts described thus far are conventional and form no part of my invention.

My improved slug positioner is mounted on a block 18 secured to frame 10 adjacent die 11 by screws 19 and comprises a plunger in the form of a rod or bolt 20 reciprocable in a guide such as a tube or barrel 21 having a bore 21a therethrough. The barrel is disposed normal to the common axis of the dies 11 and 16, as by welding to block 18, preferably so that bolt 20 reciprocates in a path parallel to that of the shear blade 14. Bolt 20 has at the forward end thereof a laterally and forwardly projecting positioning finger 22 of L-shape including a shank and a tip. The extreme forward end or tip 22a of the finger is adapted, when bolt 20 is in the position shown in Figure 2, to position the slugs 15 as advanced successively by the shear blade. The rear, laterally disposed corner 22b of the finger slides on a horizontal bearing plate 23 secured to the bottom of block 18 and extending inwardly toward die 11. Bolt 20 slides in a bushing 24 seated in the inner end of bore 21a.

A cap 25 has a threaded neck 25a screwed into the outer end of the barrel 21 and is fitted with a bushing 26. A stop screw 2'7 slidable in bushing 26 is screwed home tightly in the outer end of bolt 20 and has a coil spring 28 thereon compressed between the outer end of the bolt and the inner end of bushing 26. The spring thus constantly urges the bolt inwardly until the head of screw 27 engages the outer face of cap 25 and the length of the screw determines the inwardmost position of finger 22. Barrel 21 has a longitudinal slot 29 therein to admit a screw 30 entering bolt 20 radially. Screw 30 serves merely as a safety stop in the event of breakage of screw 27. It also prevents rotation of the bolt 20 should there be any tendency for finger 22 to kick upwardly.

The eifective position of finger 22 is that shown in Figure 2, and the finger is normally held in such position by spring 28. The finger must be retracted to an out-ofthe-way position, however, in order to permit die 16 to close on die 11. For this purpose, I mount a wedge block 31 on the side of head 17 adjacent barrel 21. The finger 22 has a rounded portion 22c adapted to be engaged by block 31, as head 17 advances to execute a forging stroke, thereby displacing the finger and forcing bolt 20 into barrel 21 against the force of spring 28. Thus the finger is moved out of the way of the advancing die as the latter is pressed home against die 11.

The complete operating cycle will now be described, commencing with the completion of one forging operation as illustrated in Figure 1. Die 16 having reached its extreme forward position, is first retracted with head 17 on its reverse stroke. Ejector pin 11a thereupon kicks out the ball formed between the dies. As die 16 moves rearwardly, bolt 20 advances under the pressure of spring 28 to the limit permitted by engagement of surface 220 of finger 22 with wedge block 31, the final position of the finger being determined by the length of screw 27 as aforesaid. As a result, when block 31 finally separates from surface 220, the bolt is advanced so that the tip porthe slug between the dies.

,17 advances to close die 16 on die 11. advances, bolt 20 and finger 22 are displaced out of the way of die 16 by block 31, just beforethe die engages 3 tion 22a of the finger is in its inwardmost position to locate the next slug.

In the meantime, shear blade 14 has advanced to engage the end of bar 13, sever the next-slug 15 and carry it to a position between the dies. The outer end of the slug engages finger 22 and the slug is thereby turned slightly in a horizontal plane so that its axis coincides with that of the dies. This condition'of the parts is shown in Figure 2. The travel of the shear blade,

the slug. As soon as die 16 has engaged the slug and pushed it into die 11, the shear blade is retracted to effect'the transfer of the slug in space from the shear blade to the dies and to permit final closing of the dies. At the same time, bar 13 is fed forward against gage stop 13a in preparation for the cutting off of the next slug.

It will be understood that stop screw 27 is bottomed in the hole in the outer end of the bolt 20 and is fixed for the size of bar being worked so as to stop the travel of the finger toward the dies at its proper position. A unitconsisting of screw 27, bolt 20 and finger 22 is provided for each particular bar Size and the required 7 unit for the size bar to be worked is placed in the machine while making ready for the run. To change to a diiferent size, the screw 27 is removed, the bolt 20 and finger 22 are withdrawn from the barrel 21 and a unit particularly designed for the new size is put in place.

The positioning means shown and described herein has several important advantages. In the first place, it is very simple in structure including only one moving part and one point of working contact. Poor alinement of the slugs with the dies and the mis-shaping of balls resulting therefrom have been minimized as well as the delays in production formerly necessary for the purpose of adjustments. As a result, a substantial increase in production per day has been achieved, as well as a reduction in scrap loss.

Although I have disclosed herein but a preferred embodiment of my invention, I intend to cover as well any change or modification which may be made without departing from the spirit and scope of the invention.

1 claim:

1. A device for accurately positioning a slug when pushed into alinement with a fixed die from a point laterally thereof by a reciprocating shear blade for engagement by a movable die reciprocating toward and from said fixed die, said device comprising a cylindrical barrel mounted on said fixed die normal to the path'of said movable die, the axis of said barrel lying in the plane determined by said die path and that of said blade, a bolt reciprocable' in said barrel toward and from the die path, a head on said bolt extending normal thereto and a finger on said head parallel to said bolt adapted to project between the dies when the movable die is retracted and to arrest a slug being advanced by said blade to position for shaping between said dies, means urging the bolt toward said die path, means limiting movement of the bolt toward said die path and coacting surfaces on said movable die and said head elfective to retract said bolt as the movable die advances toward the slug.

2. The apparatus defined by claim 1, characterized by said movement-limiting means including a screw extending longitudinally into said barrel and threaded into said bolt.

3. The apparatus defined by claim 1, characterized by said coacting surfaces including a wedging block on the movable die adapted to engage the inner end of said bolt.

4. The apparatus defined by claim 1, characterized by a bearing plate slidably supporting said head adjacent said finger.

References Cited in the file of this patent UNITED STATES PATENTS 797,934 Bidle Aug. 22, 1905 1,569,895 Svensson et al. Jan. 19, 1926 1,857,997 Brennan May 10, 1932 1,897,359 Brennan Feb. 14, 1933 1,989,398 Brennan Jan. 29, 1935 2,067,568 Grunthal Jan. 12, 1937 2,532,928 Marty Dec. 5, 1950 2,639,632 Criley May 26, 1953 

